폐 PET 해중합용 재사용 및 재생 가능한 불균일 촉매

Reusable and regenerable heterogeneous catalysts for glycolysis of waste PET

The synthesis of a porous MgA1₂O₄ spinel-supported Mn₃O₄ catalyst for polyethylene terephthalate (PET) glycolysis involves a systematic process commencing with MgAl-layered double hydroxide (LDH) as a template. Sequential thermal and chemical treatments, culminating in Mn oxide loading, yield a mesoporous structure within the MgA1₂O₄ spine], affording a substantial surface area of 278 m²/g. The strategic substitution of A13+ and incorporation of Mn cation into defects ensure the highly dispersed and strongly stabilized Mn₃O₄. The strong interaction between Mn oxide and the porous MgA1₂O₄ spinel support significantly enhanced moderate acidic and basic properties, ensuring remarkable resistance to Mn leaching during glycolysis. Utilizing the Mn₃O₄/p-spMgAl800 catalyst, a yield exceeding 95% of bis(2-hydroxyethyl) terephthalate was achieved within 3 hours at 190 °C. Remarkably, even after undergoing eleven recycling cycles with regeneration, the catalytic activity remained largely unaffected and was fully restored post thermal regeneration at 500°C.